Color changes of esthetic elastomeric ligatures evaluated with the Commission Internationale d'Éclairage color system.

OBJECTIVE: The aim of this study was to assess and compare color changes in esthetic elastomeric ligatures after 30 days in situ using a spectrophotometer and the Commission Internationale d'Éclairage (CIE) color system. MATERIALS AND METHODS: The sample comprised elastomeric ligatures of four color groups (n = 42): blue pearl (BP); colorless; white pearl (WP); and pearl. Four samples from each group were allocated in for quadrants of seven patients in a split-mouth model. Color measurements were performed with a spectrophotometer in the elastomeric ligatures as received (T0) and after 30 days in situ (T1). Variables L*, a*, and b* were compared between times (T1-T0) with Wilcoxon paired ranks; color changes were compared between groups with Kruskal-Wallis test; Dunn's test was used for multiple comparisons. Spearman's correlation was applied between CIELAB and CIEDE2000 calculations. RESULTS: All groups showed color changes (T1-T0) in a* and b*, but only the Group BP had a change in L* (P < 0.01). Group C showed the greatest lightness decrease (ΔL = -2.49 ± 0.47) (P < 0.05), the smallest yellowing (Δb = 3.17 ± 0.88) (P < 0.05), and the smallest total color change (ΔE2000 = 3.19 ± 0.85), which had no statistical difference from Group WP (ΔE2000 = 3.36 ± 0.53). Correlation between ΔEab and ΔE2000 was moderate (r = 0.59; P < 0.01). CONCLUSIONS: Esthetic elastomeric ligatures became yellowish after 30 days in situ, and there were color differences between them.

Effect of surface treatment of prefabricated teeth on shear bond strength of orthodontic brackets.

OBJECTIVE:: The aim of this in vitro study was to evaluate and compare the effects of grinding, drilling, sandblasting, and ageing prefabricated teeth (PfT) on the shear bond strength (SBS) of orthodontic brackets, as well as the effects of surface treatments on the adhesive remnant index (ARI). METHODS:: One-hundred-ninety-two PfT were divided into four groups (n = 48): Group 1, no surface treatment was done; Group 2, grinding was performed with a cylindrical diamond bur; Group 3, two drillings were done with a spherical diamond bur; Group 4, sandblasting was performed with 50-µm aluminum oxide. Before the experiment, half of the samples stayed immersed in distilled water at 37oC for 90 days. Brackets were bonded with Transbond XT and shear strength tests were carried out using a universal testing machine. SBS were compared by surface treatment and by ageing with two-way ANOVA, followed by Tukey's test. ARI scores were compared between surface treatments with Kruskal-Wallis test followed by Dunn's test. RESULTS:: Surface treatments on PfT enhanced SBS of brackets (p< 0.01), result not observed with ageing (p= 0.45). Groups II, III, and IV showed higher SBS and greater ARI than the Group 1 (p< 0.05). SBS was greater in the groups 3 and 4 (drilling, sandblasting) than in the Group 2 (grinding) (p< 0.05). SBS and ARI showed a positive correlation (Spearman's R2= 0.57; p< 0.05). CONCLUSION:: Surface treatment on PfT enhanced SBS of brackets, however ageing did not show any relevance. Sandblasting and drilling showed greater SBS than grinding. There was a positive correlation between SBS and ARI.

Effect of surface treatment of prefabricated teeth on shear bond strength of orthodontic brackets

ABSTRACT Objective: The aim of this in vitro study was to evaluate and compare the effects of grinding, drilling, sandblasting, and ageing prefabricated teeth (PfT) on the shear bond strength (SBS) of orthodontic brackets, as well as the effects of surface treatments on the adhesive remnant index (ARI). Methods: One-hundred-ninety-two PfT were divided into four groups (n = 48): Group 1, no surface treatment was done; Group 2, grinding was performed with a cylindrical diamond bur; Group 3, two drillings were done with a spherical diamond bur; Group 4, sandblasting was performed with 50-µm aluminum oxide. Before the experiment, half of the samples stayed immersed in distilled water at 37oC for 90 days. Brackets were bonded with Transbond XT and shear strength tests were carried out using a universal testing machine. SBS were compared by surface treatment and by ageing with two-way ANOVA, followed by Tukey's test. ARI scores were compared between surface treatments with Kruskal-Wallis test followed by Dunn's test. Results: Surface treatments on PfT enhanced SBS of brackets (p< 0.01), result not observed with ageing (p= 0.45). Groups II, III, and IV showed higher SBS and greater ARI than the Group 1 (p< 0.05). SBS was greater in the groups 3 and 4 (drilling, sandblasting) than in the Group 2 (grinding) (p< 0.05). SBS and ARI showed a positive correlation (Spearman's R2= 0.57; p< 0.05). Conclusion: Surface treatment on PfT enhanced SBS of brackets, however ageing did not show any relevance. Sandblasting and drilling showed greater SBS than grinding. There was a positive correlation between SBS and ARI.

RESUMO Objetivo: o objetivo desse estudo in vitro foi avaliar e comparar os efeitos de desgastes, perfurações, jateamento e envelhecimento de dentes pré-fabricados (Dpf) na resistência ao cisalhamento (RC) de braquetes ortodônticos, bem como os efeitos dos tratamentos de superfície no índice de adesivo remanescente (ARI). Métodos: 192 Dpf foram divididos em quatro grupos (n = 48): Grupo 1, sem tratamento; Grupo 2, desgaste de sulcos com broca diamantada cilíndrica; Grupo 3, duas perfurações com broca diamantada esférica; e Grupo 4, jateamento com partículas de óxido de alumínio de 50µm. Antes do experimento, metade das amostras ficou imersa em água destilada a 37oC durante 90 dias. Os braquetes foram colados com Transbond XT e os testes de cisalhamento foram realizados com uma máquina universal de ensaios. A RC foi comparada, por tratamento de superfície e por envelhecimento, utilizando-se análise de variância e teste de Tukey. Os escores ARI foram comparados entre os tratamentos de superfície usando o teste Kruskal-Wallis e o teste de Dunn. Resultados: os tratamentos de superfície aumentaram a RC dos braquetes (p < 0,01) e o envelhecimento não aumentou a RC (p = 0,45). Os Grupos 2, 3 e 4 mostraram maior RC e maior ARI do que o Grupo 1 (p < 0,05). A RC foi maior nos Grupos 3 e 4 (perfuração, jateamento) do que no Grupo 2 (desgaste) (p < 0,05). RC e ARI apresentaram correlação positiva (R2 = 0,57; p < 0,05). Conclusão: o tratamento de superfície dos Dpf aumentou a RC dos braquetes; porém, o envelhecimento não foi relevante. O jateamento e a perfuração mostraram maior RC do que o desgaste. Existe uma correlação positiva entre RC e ARI.

Correction of Buccal Dehiscence During Immediate Implant Placement Using the Flapless Technique: A Tomographic Evaluation.

BACKGROUND: The aim of this study was to evaluate a new technique for treating dehiscence buccal bone sites (Class II) with immediate implant and collagen-enriched bovine-derived xenograft blocks without a surgical flap or membrane. METHODS: Individuals with at least 5 mm of buccal bone dehiscence were selected for a flapless surgical approach to insert xenograft blocks into buccal dehiscence defects as well as the gap between implant and residual bone wall. No membrane was used. Buccal bone wall height was measured by computed tomography in the preoperative period (T0) and 6 to 12 months after procedure (T1). Likewise, buccal-lingual width of alveolar ridge as well as thickness of buccal wall was compared with the contralateral tooth. RESULTS: Fourteen patients were selected. Buccal wall height at T1 was not significantly different after 6 to 12 months between the treated and contralateral teeth, although both were greater than T0 (P <0.01). The heights ranged from 6.4 to 16.30 mm at T0, 12.8 to 25.6 mm at T1, and 14.8 to 25.29 mm in the contralateral teeth. Significant differences were observed between treated teeth (T1) and their contralateral, both buccal-lingually in the alveolar ridge (P = 0.007) and in buccal wall thickness (P = 0.003). Wall thickness ranged from 0.9 mm to 3.81 mm at T1 and 0.25 mm to 1.60 mm in the contralateral teeth. CONCLUSION: Immediate implant placement at dehiscence buccal bone sites using flapless surgery combined with xenograft blocks provided complete formation of the buccal bone wall up to the implant shoulder.

Analysis of the Influence of Food Colorings in Esthetic Orthodontic Elastomeric Ligatures.

PROPOSITION: The purpose of this study was to evaluate in vitro the color changes of esthetic orthodontic elastomeric ligatures of different shades when exposed to four food colorings commonly found in the diet of patients. MATERIALS AND METHODS: The sample consisted of esthetic orthodontic elastomeric ligatures in the colors pearl, pearl blue, pearl white and colorless, which were immersed for 72 hours in five different solutions: distilled water (control group), coffee, tea, Coca-Cola ® and wine. The color changes of the esthetic orthodontic elastomeric ligatures were measured with the aid of a spectrophotometer, at T1 - as provided by the manufacturer; and T2 - after colorings process. RESULTS: The results indicated that the esthetic orthodontic elastomeric ligatures of all initial hues are susceptible to pigmentation. Among the evaluated colors, all changed the finished look and the color of the samples tested. In ascending order, the color of the samples was as follows: distilled water, Coca-Cola®, black tea, wine and coffee. CONCLUSION: The substances that have a greater potential for pigmentation in esthetic orthodontic elastomeric ligatures were black tea, wine and coffee, respectively. All shades of esthetic orthodontic elastomeric ligatures are susceptible to color change.

Apicotomy as treatment for failure of orthodontic traction.

Objective. The purpose of this study was to present a case report that demonstrated primary failure in a tooth traction that was subsequently treated with apicotomy technique. Case Report. A 10-year-old girl had an impacted upper right canine with increased pericoronal space, which was apparent on a radiographic image. The right maxillary sinus showed an opacity suggesting sinusitis. The presumptive diagnosis was dentigerous cyst associated with maxillary sinus infection. The plan for treatment included treatment of the sinus infection and cystic lesion and orthodontic traction of the canine after surgical exposure and bonding of an orthodontic appliance. The surgical procedure, canine position, root dilaceration, and probably apical ankylosis acted in the primary failure of the orthodontic traction. Surgical apical cut of the displaced teeth was performed, and tooth position in the dental arch was possible, with a positive response to the pulp vitality test. Conclusion. Apicotomy is an effective technique to treat severe canine displacement and primary orthodontic traction failure of palatally displaced canines.

Relação entre o tipo de arco de Baume e presença de cárie proximal na dentição decídua / The relationship between Baume's arch and approximal fillings existence in deciduous dentition

Este estudo teve por objetivo verificar a prevalência e a relação existente entre os diferentes tipos de arco decíduo segundo classificação de Baume (tipo I, com espaços interdentais e tipo II, sem espaços) e a presença de cárie proximal. A amostra foi constituída de 156 crianças, faixa etária entre 3 e 5 anos, que procuraram atendimento na Clínica de Odontopediatria da UFSM. O exame clínico foi realizado pelos alunos e os dados coletados a partir das fichas de anamnese e exame dos pacientes. Foi feita análise pelo programa Epi-Info 6.04d, sendo estabelecido para todos os testes o nível de significância de 5%. Obteve-se no arco superior 61,70% e 38,30% arcos tipo I e II, respectivamente. Para o arco inferior os valores foram de 54,70% para arcos do tipo I e 45,30% para o tipo II. Observou-se a presença de arco tipo I superior com lesão cariosa proximal em 45,6% dos casos e sem lesão em 54,4%. Para o tipo I inferior, os valores para os arcos com e sem lesão foram de 32,9% e 67,1%, respectivamente. Já para pacientes com arcos do tipo II superior, a porcentagem da presença de lesão proximal foi de 66,7% e ausência de 33,3%. Nos casos de tipo II inferior as porcentagens para arcos com e sem lesão foram de 66,7% e 33,3%, respectivamente. Os resultados permitiram concluir que existe relação estatisticamente significativa entre tipo de arco decíduo e presença de lesão cariosa proximal, sendo a ausência de espaços interdentais prevalente para doença.